Bio Materials

BIO

Archieved

The University of Waikato is where my lab is based. I operate within the Chemistry Department , which is a typical mainstream New Zealand University Chemistry Department which plays host to a large range of research including my niche area of biomaterials research into bone substitutes. The University of Waikato is located in Hamilton, New Zealand’s largest inland city, population 113,000 situated about 180 km south of Auckland. The countryside surrounding Hamilton is rich and fertile with the Waikato being regarded as a prime agricultural area and home to many dairy farms producing the so called “white gold” (otherwise known as milk) that is at the basis of New Zealand’s globally successful dairy industry. Although sheep numbers are down approximately 20 million to about 40 million, the number of cows are up due to the value of dairying and there is roughly one cow per person in New Zealand now [4 million cows] and a goodly number of these are located in the Waikato region. Cows are behind much of the prosperity in the Waikato region of New Zealand. The Cooperative Dairy conglomerate Fonterra controls much of the Dairy Industry in New Zealand. (Photograph used with permission from the University of Waikato.) As I work within a Chemistry Department with a broad ranges of interests, my research interests are also very broad with biomaterials being just one facet of a diverse range of research topics. In fact I have research projects that dedicated MSc and PhD students are working on at the moment which span nanotechnology, environmental chemistry, spectroscopy with electrochemistry, soil science, organic NMR, as well controlled release drug and other active agents delivery in addition to my research associated with inorganic biomaterials. I also have a wide range of contacts with industry which helps due to the governmentsponsored funding I am able to access via companies so students can do Masters and PhD projects with an applied bent to the topic.

My introduction into biomaterials occurred during a postdoctoral stint in Nagoya, Japan. I obtained an STA fellowship to spend two years there. The research topic was on developing substrates that could stimulate deposition of calcium phosphate at the surface so in a sense was to do with biomimetics. There in the then National Industrial Research Institute of Nagoya “NIRIN” amongst an unbelievable number of near constant sushi and office welcoming parties, I developed a technique known broadly as “phosphorylation” for modifying organic substrates so that calcium phosphate deposition would be stimulated on such surfaces after a Ca(OH)2 presoak prior to soaking of the modified substrate in the famous “Simulated Body Fluid” as initially reported by Kokubo et al from Kyoto. In my initial studies cotton was modified and I was able to deposit hydroxyapatite onto it with this method. The method was referred to and adapted for use up by various groups globally to stimulate deposition on various unusual substrates as bizarre as bamboo or in some cases to introduce phosphate functionalities into natural polymer materials. My biomaterials research at Waikato is primarily on use of cattle bone as bone substitutes. The work was initiated in 1996 in collaboration initially with the Meat Industry Research Institute of New Zealand with funding assistance from the Foundation for Research, Science and Technology. It led to the development of bleached and defatted cancellous bone materials which were proven to be osteoconductive when implanted in sheep in trials in 2001. The work extended into research on use of cattle bone as a plasma spray feedstock and then to its present form where the bone was sintered (rather than defatted/bleached) and then infiltrated with an organic macromolecule like polycaprolactone or chitosan to produce a stronger product. The infiltration work was carried out in collaboration with my colleague Dr George Dias who is at the University of Otago’s Anatomy and Structural Biology Department . The bone product worked on was granted a patent in 2009 and a company was created around it known as GRAFTOSS. Work is continuing to develop this technology.